M3.76: Attributes panel with overprint, centre point, path direction, fill rule, image map, URL and note

Window > Attributes (Cmd+F11) shows Overprint Fill/Stroke, Show/Don't Show
Center, Reverse Path Direction Off/On, the non-zero / even-odd fill rule,
Image Map, a URL field with recent URLs and a Browser button, and a note.
New commands attributes.set and path.setFillRule; path.reverse takes ids and
reversed; attributes.info reports every value. Objects keep the attributes in
Node.attrs. SVG export wraps linked objects in <a>, and import reads links
back. The canvas draws the centre point of selected objects that show it.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

crates/effects/src/bake.rs

@@ -147,6 +147,8 @@ fn piece(d: &mut Document, n: &Node, path: PathData, rule: FillRule, item: Appea
         trace: None,
         wrap: None,
         graph: None,
+        // The group keeps the URL (one link around the pieces).
+        attrs: None,
         kind,
         ..n.clone()
     }